in the japan airlines case, the battery caught fire, ntsb chair says there is evidence of short circuiting. when high temperatures trigger an uncontrollable reaction. >> the photo on the right and you can see the cells outlined in red, show the eight damaged cells of our battery that we're investigating in the lab. >> reporter: hersman says among the battery's eight cells, three were heavily damaged. they are trying to figure out that those are different than others. >> we're working very hard to determine what happened and why it happened. we'll look at failure scenarios and coordinating with colleagues around the world. >> reporter: aviation authorities in japan are also looking at the battery problem. they have been examining the charred front battery from all nippon airways 787. officials detected smoke coming from it last week. the crew made an emergency landing in western japan. investigators say the flight data recorder gives no indication that excessive volt age ran through the battery. but they are not ruling out the possibility of an overcharge. >> translator: we do not see evide